Conversion Floor Structure Questions Checklist

Walk the space slowly and note where the floor sounds hollow and where it sounds solid, marking on a rough sketch anywhere the sound changes.

A change in sound part way across a room often means the floor is not all one thing, which is worth flagging before anyone assumes it is.

Look for an access hatch, a previously lifted board or a low level vent outside, and record anything visible from where you can safely stand or kneel.

Small existing openings often answer questions that would otherwise need something taken up, and looking at them asks nothing of anybody.

Record what an existing opening already shows you and stop there; taking up boards or entering the space beneath is not owner work.

Note which way any floorboards or joints run and whether that direction changes anywhere, then take that observation to a professional rather than reading anything into it.

The direction is easy to record and genuinely useful, but what it implies about what supports what is not an owner conclusion.

Record whether this floor sits at the same level as the space next to it, or steps up or down, and by roughly how much in ordinary terms.

The level difference between a converted space and the rest of the house shapes the whole scheme and is frequently discovered late.

Walk outside and note any airbrick or vent below the level of this floor, how many there are and whether any is blocked, painted over or buried by soil.

What happens outside below the floor line often matters more to the conversation than anything visible inside the room.

Check any survey, sale particulars or previous work paperwork you hold for a description of this floor, and note what it says without treating it as current fact.

A description written for another purpose years ago tells you what somebody believed at the time, which is worth passing on and worth nothing more.

Walk deliberately across the space and note where the floor gives or bounces, whether it happens near the middle or at one end, and whether anything on a shelf rattles.

Owner reports of movement are genuinely valuable information, and they are the one thing a visiting professional cannot observe in a short visit.

Note where the floor creaks, whether a board has been screwed down or patched at some point, and whether the creaking has changed since you have been here.

Patched or refixed boards mark the spots where somebody has already had to deal with something.

Set something round on the floor in several places and note where it rolls and in which direction, then record the pattern rather than a single result.

A consistent direction of fall across a whole floor is a different observation from one dip in a corner, and only a pattern shows the difference.

Whether any slope or movement matters is for a qualified professional to establish; nothing observed this way should be interpreted by an owner.

Look along the skirtings and the edges of the floor for gaps that have opened, and note whether any gap runs along one wall or appears at a corner only.

Edges tell a story about what has moved and in what direction, and they are the easiest place for an owner to look.

Note whether any part of the floor feels colder or damper than the rest, whether stored items in that area have ever gone musty, and where exactly that happens.

The corner where the cardboard boxes went soft is worth reporting plainly, and it is often the first mention of an underlying issue.

Record what heavy things stand on this floor now and where, including a freezer, a workbench, stored materials or a vehicle if the space is a garage.

What the floor already carries is useful context, and the answer is often that it carries very little in the area you want to change.

List what the converted space would actually contain, including bookcases, a bath, a large tank, gym equipment, stored files or a heavy piece of furniture.

This list is exactly what a professional needs in order to consider the floor, and only you can write it.

What a floor can carry is for a suitably qualified professional to establish; never assume that because something fits it is fine to put there.

Note whether the space would be slept in, used by a group of people, or used by children, and raise each of those uses when you first describe the project.

How a room is occupied changes what has to be discussed and confirmed locally, and it is a detail owners often leave until late.

Record whether the space would be divided by a new partition and roughly where that partition would land on the floor.

A partition is a line of extra weight in a specific place, and where it lands is a question rather than an owner decision.

Where a new partition can be positioned is a matter for a qualified professional to consider, not something to settle from a layout you like.

Note any fixed appliance, cylinder or tank you hope to place in the space, and where you imagine it standing, before a layout is drawn around it.

A water filled item in a converted space is one of the first things a professional will want to know about.

Write down whether you have a stone, tile or other solid finish in mind, and treat it as something to raise early rather than as a decoration decision.

Finish choices that seem cosmetic are sometimes the ones that need discussing first, and they get made late by default.

Record what sits beneath this floor and whether it would stay in use, whether that is a room, a garage, a cellar, a void or bare ground.

What is underneath frames every question about the floor, and it is often described loosely as just a void when nobody has looked.

Note every pipe and cable you can see entering or leaving the floor zone, where each one appears and what you believe it serves.

Even an incomplete list is better than none, and it gives everyone a starting point for what would have to be worked around.

Record whether any form of underfloor heating already exists here or is wanted, and ask what either answer means for what the floor becomes.

Heating in the floor changes the build-up conversation completely and needs raising before a finish is chosen.

Note whether a meter, stopcock, incoming supply or gas entry sits within this space or in the floor zone, and photograph each one where you safely can.

Supply entry points constrain layouts in ways nobody expects, and they are often in exactly the corner somebody wants to use.

Anything to do with a supply entry, meter or isolation point is for the relevant supplier and a qualified professional to deal with.

Note where a waste pipe would have to cross this floor if a fitting is wanted, and ask what that would mean for the level rather than assuming it can be hidden.

A waste run through a floor is the classic reason a level ends up higher than anybody intended.

Record any patched, replaced or differently coloured area of the floor, since it usually marks where somebody has been in before.

Patches are a free record of the history of the floor, and they point at where services are most likely to run.

Ask how anything left within the floor would be reached again later, and note the answer alongside where each item is.

Access after the work is the question that never gets asked, and it is only ever simple to answer beforehand.

Look where the floor meets each external wall and note any staining, blistered paint, crumbling plaster or a skirting that has been replaced.

The junction with an outside wall shows problems earlier than the middle of a room, and it is easy to look along on your hands and knees.

Note whether the floor appears to continue under a partition or to stop at it, and mark on your sketch which walls in the space are original and which look added.

Whether a wall stands on the floor or the floor stops at the wall is a genuine question, and owners can usually see the clues.

Record every threshold, step and change of level at the edges of the space, including the one at the door you would use most.

Thresholds decide how a converted room reads as part of the house, and they are easy to forget when you look only at the middle.

Note whether the scheme would need a new opening through the floor for a stair or a hatch, and mark roughly where it would go on your sketch.

An opening through a floor is one of the biggest questions in any conversion and needs to be raised at the first conversation.

Forming any opening through a floor is a matter for a qualified designer and engineer; nothing here indicates whether or where one is possible.

Record any hearth, chimney breast or recess meeting the floor in this space, and note whether the floor changes construction at that point.

Floors often do something different around a chimney breast, and the change is visible where a finish stops.

Note anywhere the edge of the floor is actually visible, such as a step down into a garage, the lip of an outbuilding slab or a threshold at a door.

A visible edge is the only free look at the floor build-up most owners ever get, and it deserves a photograph.

Measure the height from floor to ceiling in several places, record what you get with the date, and label it plainly as your own rough measurement.

An owner measurement is a starting point, not a survey, and labelling it prevents anyone designing from a figure taken casually.

Ask how much of the height available would be taken by whatever build-up the floor needs, and treat the answer as the constraint the rest of the scheme lives with.

The build-up is agreed quietly and then everything else has to fit around it, so it is worth asking about early.

What build-up a converted floor needs is a design matter for a qualified professional and depends on requirements to confirm locally.

Note where the lowest point overhead is, whether that is a beam, a duct, a boxing or a sloping section, and mark it on your sketch.

The lowest point governs how the room feels, and it is rarely where people are standing when they judge the height.

Record which doors open into or out of the space and what would happen to each of them if the finished floor ended up higher than it is now.

Doors and their frames are the first casualties of a raised floor and the last thing anyone thinks about.

Write down how you would want the finished floor to meet the adjoining space, and whether a threshold strip, a shallow ramp or a change of material would suit you there.

Deciding this yourself, early, is better than inheriting whatever falls out of the construction.

Decide and record which matters more to you here, a floor continuous with the rest of the house or a build-up that does more for comfort, and say which you would give up.

Whichever way this goes, somebody decides it; the only real question is whether the household is in the room when that happens.

Note which floor questions keep coming back with an answer that begins with probably, and list them separately as things nobody actually knows yet.

The pattern of hedged answers is the clearest signal that something needs looking at rather than discussing further.

Ask who would open up part of the floor if that becomes necessary, what would be exposed, and how the floor would be made good afterwards.

Opening up is routine work for the right person, but nobody explains it in advance unless asked.

Opening up any part of a floor is work for a qualified professional, including the decision about where such an opening can be made at all.

Write down which floor answers you would want before committing to a finish, a fitting or a layout, and keep that list in front of you when decisions are made.

Order and commitment tend to run ahead of information, and a written list is the only thing that slows that down.

Note how much of the space would have to be emptied before anyone could see the floor properly, and arrange that before a visit rather than during it.

A visit to a full garage or a loaded loft produces a shorter and less useful conversation than the same visit to an empty one.

Ask what would be looked at first if the floor turned out to be different from what was expected, purely so the sequence is familiar before it is needed.

Hearing the order in which things get investigated makes a later surprise a process rather than a crisis.

Keep every floor observation, photograph and sketch dated and labelled as your own, so nothing you noticed gets quoted back as if it had been established.

An owner note that gets mistaken for a finding is worse than no note at all, and labelling it takes a moment.